In the prior art, in order to prevent generation of the failure due to the wear or the failure of the rotating body or the sliding member, a thorough overhaul and a visual inspection are applied periodically to the machinery facility such as the railway vehicle facility, the machine tool, the windmill, or the like In the thorough overhaul and the visual inspection, the rotating body or the sliding member is removed from the machinery facility and decomposed after the facility is operated for a predetermined period, and then the skilled expert who handling the inspection checks a degree of the wear, the presence or absence of the flaw, or the like of respective constituent parts with a skilled eye. As major defects that are found by the inspection, in the case of the bearing unit, there are the indentation due to the capture of the foreign matter, etc., the flaking due to the rolling contact fatigue, other wear, and others. Also, in the case of the gear, there are the fracture or wear of the teeth, or the like. When the person who handles an inspection detects an abnormality such as unevenness, wear, and the like., which are not found in a new rotating body or sliding member, such person exchanges the defective parts for the new one and then assembles the rotating body or the sliding member once again (see the catalog “ROLLING BEARING” (CAT.No.1101e, page B340 to page B351) issued by Nippon Seiko K. K.).
However, in the method of decomposing the overall machinery facility and inspecting the failure with the eye of the person in charge, a decomposing operation of removing the rotating body or the sliding member from the machinery facility and a fitting operation of fitting again the inspected rotating body or sliding member into the machinery facility require much time and labor. Thus, such a problem existed that a substantial increase in an upkeep cost required for maintaining, managing, or the like the machinery facility is brought upon.
In particular, in the case of the windmill, most of the windmills are used in an offshore area and also the number of the installed windmills is large. It is the existing circumstances of maintaining/managing operations of the windmill that the person in charge of the maintenance goes to the installation location of the windmill and then conducts the inspection of rotating parts of the windmill there For this reason, such a problem existed that it take an enormous time and cost to maintain/manage the windmill and thus a maintenance efficiency is poor. Also, it is possible that the inspection itself causes the defect of the rotating body or the sliding member. For instance, the indentation that has not been put before the inspection is made on the rotating body or the sliding member when the machinery facility is reassembled after the decomposition and the inspection, and so forth. Also, since the person in charge of the inspection must check a number of bearings with the eye within a limited time, there existed the problem that such a possibility still remains that such person fails to find the defect. In addition, since a decision level of the defect varies between individuals and thus exchange of the parts is carried out even though the defect is not found substantially, the above inspection entails a useless cost.
Also, in order to overcome the disadvantages caused by such visual inspection, it is studied that the sensor for sensing the sound or the vibration generated during the rotation of the bearing is provided on the body of the vehicle in which the bearing is used, and then the abnormality such as the wear, the failure, or the like of the bearing is sensed based on the sensed signal of the sensor.
However, in the case where the sensor is fitted onto the body of the vehicle, an SN ratio of the sensed signal from the sensor is worsened because the sensor is provided away from the bearing. Thus, there existed such a problem that it is difficult to sense/decide the abnormality with high precision.
Also, as an bearing unit in the prior art, in a bearing unit 1100 having a sensor module shown in FIG. 50, a module hole 1103 is formed on an outer peripheral surface of an outer ring 1102 of a rolling bearing 1101, and then a module 1104 into which a speed sensor, a temperature sensor, and an acceleration sensor are installed is inserted/fixed into the module hole 1103. Then, sensed signals generated from respective sensors in the module 1104 are transmitted to a remote processing unit provided in the locomotive, which pulls the freight cars and the passenger cars in which the rolling bearings 1101 are provided, via the communication channel.
As to the speed, the instantaneous speed of the journal is sensed based on the pulse generated by the rotating wheel, and then such speed and the speed of other bearings that are operating under the same conditions are compared with each other. Thus, the overall period history to which the bearing assembly is subjected is saved/recorded. As to the temperature, such temperature and the temperature of other bearings that are operating under the same conditions are compared with each other by a simple level detection. As to the vibration, a simple RMS measurement of an energy level is carried out over a predetermined period of time, and then such energy level and the past energy level stored in a processing unit are compared with each other. Thus, such energy level and the energy level of other bearings that are operating under the same conditions are compared with each other (see JP-T-2001-500597 (pp.10 to 16, FIG. 1)).
Also, as another configurative example of the bearing unit, in an abnormality sensing unit 1110 of the rolling bearing unit shown in FIG. 51, a sensor fitting hole 1113 is formed in the lower end portion of an outer ring 1112 of a double row tapered roller bearing 1111, and then a sensor unit 1117 having a rotation speed sensor 1114, a temperature sensor 1115, and an acceleration sensor 1116 therein is inserted/supported into the sensor fitting hole 1113 (for example, see JP-A-2002-295464 (pp.4 to 5, FIG. 1)).
In addition, as other configurative example of the bearing unit, in a sensor built-in rotation supporting member 1120 shown in FIG. 52, a sensor fitting hole 1123 is formed in the lower end portion of an outer ring 1122 of a double row tapered roller bearing 1121, and then a sensor unit 1126 having a rotation speed sensor 1124 and a temperature sensor 1125 therein is inserted/supported into the sensor fitting hole 1123 (for example, see JP-A-2002-292928 (pp.4 to 5, FIG. 1)).
Further, as other configurative example, an abnormality sensing unit 1130 of the bearing unit shown in FIG.53 has a pickup 1132 for converting a mechanical vibration of a bearing 1131 into an electric vibration to output, an automatic gain control amplifier 1133 for amplifying an output of the pickup 1132, and a 1 to 15 kHz bandpass filter 1134 for removing noises generated from the driving system and other mechanical systems from the output of the amplifier 1133. Also, the unit 1130 has a root-mean-square calculator 1135 for calculating a root mean square value of the output of the bandpass filter 1134 and supplying the value to a gain control terminal of the automatic gain control amplifier 1133, an envelope circuit 1136 for receiving an output of the bandpass filter 1134, a root-mean-square calculator 1137 for receiving an output of the envelope circuit 1136, and an alarm circuit 1138 for receiving an output of the root-mean-square calculator 1137 and issuing an alarm by using a lamp or a contact output when such output value exceeds a predetermined value (for example, see JP-A-2-205727 (pp.2 to 3, FIG. 1)).
Furthermore, as other configurative example, an abnormality diagnosis system 1140 of the rolling bearing shown in FIG. 54 has a configuration that includes a microphone 1142 arranged in vicinity of a rolling bearing 1141, an amplifier 1143, an electronic device 1144, a speaker 1145, and a monitor 1146. The electronic device 1144 is a calculating/processing unit, and has a transducer 1147 as a converting portion, a HDD 1148 as a recording portion, an abnormality diagnosing portion 1149 as a calculating/processing portion, and an analog converting/outputting portion 1150 (for example, see JP-A-2000-146762 (pp.4 to 6, FIG. 1)).
Besides, as other configurative example, in an abnormality diagnosing method and an abnormality diagnosing system 1160 of the bearing shown in FIG. 55, an electric signal waveform that a sensor 1161 outputs is converted into the digital file by an analog/digital converter 1162, then is sent out to a waveform processing portion 1163, and then is subjected to the enveloping process by the waveform processing portion 1163 to get an envelope spectrum. Then, an inner ring flaw component, an outer ring flaw component, and a rolling element flaw component, which are particular frequency components of the bearing constituent parts, are extracted from the envelope spectrum by the waveform processing portion 1163 in the extracting step by using predetermined equations. Then, a calculating portion 1164 executes the calculating step, a deciding portion 1165 executes the comparing step, an outputting portion 1166 outputs the decided result, and a speaker 1167 and a monitor 1168 inform the inspector of the result (for example, see JP-A-2001-021453 (pp.5 to 6, FIG. 1)).
However, in the configurations of the bearing unit set forth in JP-T-2001-500597 and JP-A-2002-295464, since the sensor fitting hole is provided in the outer ring, the type of the outer rings constituting the bearing is increased such as the outer ring in which the hole is not provided and the outer ring in which the hole is provided. As a result, there is a possibility of generating the installing error, and the like, and also a lot of man-hours are needed to manage the parts. Also, it is possible that the outer ring with the hole hinders the sealing performance in the bearing.
Also, in the abnormality diagnosis system set forth in JP-A-2-205727, JP-A-2000-146762, and JP-A-2001-021453, merely the measure against the vibration-noise is disclosed. In the case where the bearing is used to support the axle of the railway vehicle, it is possible that this diagnosis system decides a great shock generated when the railway vehicle passes over the rail joint as an abnormal signal. Thus, the abnormality decision may be largely affected.
Also, in order to overcome the disadvantages caused by the overhaul inspection or the visual inspection, there is proposed a monitoring system that includes a sensor for sensing the sound or the vibration generated during the rotation of the bearing and an information processing system for analyzing a sensed signal of the sensor to decide whether or not the abnormality is generated and uses a personal computer as the information processing system (for example, see JP-A-2002-71519).
However, the personal computer used as the information processing system in the monitoring system in the prior art has normally such a configuration that a motherboard and an interface for receiving an output of the sensor are installed into a general-purpose casing. Thus, the information processing system needs a relatively large installing space and also has a tendency that does not endure the vibration, and the like well.
For this reason, in order to prevent an influence of the vibration on the bearing unit, etc., a space in which the personal computer is provided must be secured in the position that is distant from the bearing unit, etc. to some extent. In addition, this monitoring system becomes large in size. Therefore, in the case of the machinery facility in which the assurance of the large installing space is difficult, such a problem has arisen that such monitoring system is of little utility.
Also, in order to prevent a deterioration of the SN ratio of the signal sensed by the sensor, it is preferable that the sensor should be incorporated into the constituent parts itself of the bearing unit if possible. However, the personal computer that cannot stand up to the external vibration, and the like and is large in size must be separated as far as possible away from the bearing unit, or the like as the vibration generating source. As a result, the personal computer is apart from the sensor at a predetermined distance or more, and thus it is possible that the problem such as a reduction in a sensing precision due to the influence of the external noise on the information transmission path between the sensor and the personal computer, or the like is caused.
The present invention has been made in view of the above problems, and it is an object of the present invention to provide a high-precision machinery facility abnormality diagnosis system capable of deciding the presence or absence of an abnormality in a state of normal use without decomposition of a facility like a machinery facility such as a railway vehicle facility, a machine tool, a windmill, or the like, which requires much time and labor to decompose, and thus capable of reducing maintenance/administrative costs and being hardly affected by the noise, and the like.